Air painting device



Nov. 3, 1936. v- J. A. PAASCHE 2059,706

AIR PAINTING DEVICE Filed July I6, 1951 Patented Nov. 3, 1936 UNITEDSTATES PATENT OFFICE 11 claims.

The invention relates generally to air painting devices and moreparticularly has reference to painting devices in which the applicationof paint, color coats, or the like, is produced by.

air under pressure.

An object of the invention is to provide a device of this nature whichembodies new and im; vproved means for actuating the device.

Another object of the invention resides in the provision of such adevice in which the pressure of the air supplied to the device isutilized in a novel manner to actuate the means by which the device iscontrolled.

More particularly stated, an object of the invention resides in theprovision oi an air painting device for applying paint or othersurfacecoating material by means of air under pressure, which deviceembodies a hollow barrel having valve means therein for controlling thepassage of paint and air therethrough, and'means in said barrel arrangedto be actuated by incom ing air to open said valve means, said partsbeing so related that the air after actuatingl said valve means passesthrough said barrelto produce a :dow of the coating-material from thedevice.

In conjunction with the foregoing objects, the invention has as anobject the provision of a novel device which is adapted to be used inbanks or batteries of several devices, all of which f may be under thecontrol of a Single instrumentality.

Other objects and advantages will become apparent in the followingdescription and from the accompanying drawing, in which:

AFigure l is a view partially in plan and partially in elevationillustrating an apparatus embodying the features of the invention.

Fig. 2 is a longitudinal, axial section on an enlarged scale through theair painting device.

Figs. 3 and 4 are views partially in section of different types of spraynozzles Iand their associated control elements utilized as replacementassemblies for the device shown in Fig. 2.

Fig. 5 illustrates an extension and a modified form of spray nozzle foruse in connection with the device illustrated in Fig. 2.

Fig.v6 is a view on a reduced scale of a modified form of apparatus. Y

In describing the preferred embodiment of the invention, it will beconsidered that the device is adapted for atomizing paint or othercoating' material by air under pressure. It should be understood,however, thatthe device is capable of atomizing liquids, other thanpaint, by pressure uids, other than air, and the terms paint and air areherein employed, not in`a limiting sense, but for the purpose ofsimplifying the discussion of the invention. Moreover, while theinvention is susceptible of various modiiications and alternativeconstructions, I have shown in the drawings and will herein describe indetail the preferred embodiment, but it is to be understood that I donot thereby intend to limit the invention to the specific form dis- 10closed, but intend to cover all modifications and alternativeconstructions falling within the spirit and scope of the invention asexpressed in ,the appended claims.

In the embodiment of invention `which has 15 been selected for thepurpose of illustration, and with particular reference to Fig. 2, lthebody of the spraying ydevice comprises a barrel I0' in the form of atubular member which' is preferably cylindrical and has a .portion I'Iof restricted size at one end thereof. The outerend of the restrictedportion II has an annular flange III thereon providing an abutment foran inturned shoulder on a gland .I2 to hold the gland rotatably on theportion II. The gland is internally screw threaded to engagecomplementary screw-threads on a' head I3 having an internal passagewayi4 at the front end thereof. Paint or other material to be sprayed issupplied to the passageway I4 through an integrally formed 3d nipple I5.The union between the head I3 and barrel portion II allows the head tobe rotatably adjusted about its axis so that the paint may be suppliedto the device from any angle through the nipple l5. The head is provided35 with a longitudinal passageway I6 for air, which passagewaysubstantially divides the head into two concentrically arranged -partswhich are maintained in position by the integral formation of the headand nipple I5. 40

The front end of the head receives a nozzle assembly, generallydesignated at I'I, arranged to be detachably secured thereto. The nozzleassembly comprises a centrally disposed tapering tip I8 having atapering axial bore I9 commun- 45 cating with the paint passageway I4and an annular passageway 20, registering with the air lpassageway I6.The tip is held in assembled but detachable relationship on the head bysuch means as a nut 2I engaging the tip and having 50A tionship to thetip by such means as a gland 23 carried by the nut 2I, cooperates withthe tip in providing an annular restricted emission port 24 about therestricted mouth 25 of the bore I9. 'I'he flow of air under pressurethrough the port 24 is effective in a manner which is well-understood tocreate and eject a spray of paint from the device.

Within the bore I9 a valve seat is provided which cooperates with avalve 26, herein shown as a needle valve, for controlling the flow oi'paint from the device. The valve 26 is actuated by means of anintegrally formed valve stem 21 which extends'rearwardly and axiallythrough the head I3 and into the larger portion of the 'barrel III. Thehead I3 is provided with a. rearwardly facing axial bore 28 to receivepacking 29 of any suitable character. Preferably, the packing is held inplace by means which may be removed from the device as a unit in orderto permit replacement thereof by a corresponding unit of diierent size.To this end, the rear face of the head I3 ares outwardly, as at 30, fromthe bore 28 to cooperate with a complementary surface formed on the endof a packing and bearing member 3 I. This member has an annular shoulder32 thereon arranged to abut an outwardly facing shoulder 33 provided onthe end of the restricted portion I I of the barrel. Thus, when the headI3 is screwed into the restricted portion Il, the bearing member vwillbe securely clamped between theY shoulder 33 and the end of the head.

The front end of the bearing member is radially bored, as at 34, to formwhen the parts are assembled a continuation of the bore 28. Hence, thebore 34 may, and usually does, receive a p0rtion of the packing material29. The rear portion of the bearing member is apertured to per-4 mit thestem 21 to extend therethrough. Sur- Y disposed rearwardly of therestricted portion II,

defines a cylinder compartment 31 having a rear wardly directed openface arranged to be closed by an end` cap 38 detachably screw-threadedonto the barrel. Within the chamber 31" is located means for operatingthe needle valve 26, which means is responsive to the pressure of theair as the air is delivered to the nozzle. Thus, the end of the valvestem 21, which extends into the chamber 31, passesthrough a pistonassembly, generally designated 39, arranged for reciprocating movementwithin the chamber. The piston assembly comprises a ceninal, elongatedhub 40 which preferably has a packing assembly mounted in a bore 4|!atherein and similar generally to thatv located forwardly thereof in thebores 28 and 34. The hub 40 has an integrally formed annular flange 4Ithereof arrangedvto cooperate with a disk 42, having screw-threadedengagement with the hub 48, to secure a exible piston washer 43 ofleather or the like to the hub. Air under pressure is introduced at somepoint intermediate the piston assembly and the nozzle and itis'preferred that the barrel I8 be apertured, as at 44, near the frontend of the chamber 31 to provide an air inlet port which is defined bythe customary nipple 45. The piston assembly 33 is spaced from the'frontend of the chamber 31` a distance sumcent to clear the port 44.

Vtrolling and paint controlling valves.

It will be apparent from the foregoing that the introduction of airthrough the aperture 44 will cause the piston. to move rearwardly. Thevalve stem 21 beyond the piston assembly carries a piston engageablehead 49 spaced a short distance therefrom to provide for a limitedamount of lost motion before the piston contacts the head to move itrearwardly and thereby open the needle valve 26. Return movement of thepiston i`s effected, in the present instance, by suitable resilientmeans bearing between the end cap 38 and the piston assembly 39. Thus,opposed bosses 46 and 41, on the disk 42 and end cap 38 respectively,provide seats for a helical spring 48 arranged to exert a force fornormally holding the valve 26 seated.V The boss 46 incidentally is thepart of the piston assembly which engages the head 49. `The rear face ofthe head 49 is cupshaped to receive one end of a second and smallerhelical spring 50, the other end of which is centered about a pin Icarried by a tension adjusting screw -52 mounted in the end cap 38. Ihusthe force exerted on the valve 26 may be adjusted as required.

In order positively to insure operation of the piston whenever air underpressure is admitted to the inletv aperture 44, an air control valve isinterposed between the aperture 44 and the nozzle. This air controlvalve preferably is actuated by the piston mechanism 39 to open prior tothe opening of the needle valve 26. In the present embodiment, theforward end of the piston hub 40 is tapered, as at 53, to form a valvemember. l'lihebarrel I0 is provided with an in' ternl annular iiange 54defining a central aperture and finished to provide a valve seat for thevalve member 53.

When the parts are assembled, the arrangement is such that the valves 26and 53 open and close according to the movements of the piston assembly39'. The valve 53 controls the flow oi! iiuid from the air inletaperture 44 to the nozzle member and, when the device is 1noperative,prevents the iiow of air to the nozzle. It. will be evident, therefore,that, when-air under pressure is first admitted to the device, thepiston assembly 39 will be ,positively moved rearwardly of the barrel tofirst open the air valve` 53 and permit a ow of atomizing air to thenozzle. Subsequently the boss 46 engages the head 49 on the valve stemand opens the needle valve 26 gradually allowing paint to ow through thenozzle into the air stream. The piston will be held in its rearwardposition as long as air is admit-ted to the barrel, but as soon aspressure on the piston is relieved, the springs 48 and 58 operateindividually to'close both the air con- While the present device may beused by itself, it is as readily capable of' being employed in banks orbatteries of two or more devices which are controlled and actuated byasingle instrumentality. The use of severalY devices is desirable whenthe devices are employed in connection with an automatic paint applyingmachine such, for example, as that illustrated anddescribed in mycopending application Serial No. 523,393 med March 1s, 1931.

One preferred form of means for actuating one or more ofthe paintapplying devices is shown in Fig. 1. Air under pressure is supplied tothe device in the following manner: A conduit 55 it connected through aswivel connection 56 with the air inlet nipple 45. The conduit 55 ispreferably in the form of a rigid pipe or tube which sheaves is engagedby a universal bracket E1 for supporting the device from a stationarypart 58. A hexible conduit 59 provides communication between the rigidconduit 55 and a valve mechanism, generally indicated at 60, from whicha conduit el leads to a source of air under pressure (not shown). Thevalve mechanism 60 includes a reciprocable valve member 62 which isnormally held in valve-closing position by a spring te. A valve stemlili, connected with the valve t2, extends outside the valve housing andis engageable by a pivoted valve-actuating cam t5 mounted externally ofthe valve mechanism. By this arrangement, the means by which the deviceis manipulated may be mounted at a considerable distance from the deviceitself as, for example, adjacent the edge of a table or moving conveyeron which articles to be painted are `mounted. Such means as a spindle'65, carried by the table and having a cam follower 6l thereon arrangedin the movement oi the table to engage the cam 65, may be employed toactuate the valve at predetermined points in the movement of the table.Preferably, a cut-oil valve 68 is interposed' between the valvemechanism 60 and the device for preventing actuation of the device asdesired.

vWhen several of the devices are employed as a battery, all of suchdevices may be actuated by the single valve mechanism SIB. In such acase, a branch conduit 69 establishes communication between the conduit59 and the several additional devices. As a result, when the valvemechanism 60 is actuated, air under pressure is delivered to the barrelof each device to actuate the devices simultaneously. Obviously, if eachdevice is provided with a cut-oil valve 68, they may be selectivelyused. A conduit 'I0 supplies paint from a suitable source (not shown) tothe nipple I5.

Fig. 6 shows a modied form of the structure shown in Figs. 1 and 2wherein the atomization may be accomplished by air under less pressurethan that which actuates the piston assembly.

- This end is attained by providing a pressure relduction valve betweenthe supply line and the ably on the side of the head I3 opposite thepaint inlet nipple I5. This conduit Iiil is controlled by a manuallyoperable needle valve I8b of customary construction. for regulating theair flow to the nozzle. In this construction the passageway I 6` betweenthe inlet mouth oi the conduit I6l and the piston assembly is closed.Thus, the device is adapted to be operated by air under low pressurewhile the piston is actuated by full pressure and thereby provides asimple, economical and positively operating structure.

Inasmuch as the present device is particularly adaptable for use inconnection with paint applying machines which generally are capable ofhandling many diierent types of objects, the invention provides means bywhich the device may be readily adjusted or converted to adapt it toproperly coat these diierent types of objects. Thus, the nozzle assemblyis readily detachable from the head I3 to allow the characteristics ofthe coating spray created by the device to be varied to provide a ilneror a coarser spray. This particular adjustment, of course, has itslimits and, where the nature of the spray desired is beyond theselimits, a replaceable assembly such as that shown in Figs. 3 or 4 isprovided.

The assembly shown in Fig. 3 embodies a nozzle and head assembly,similar in general structure to that illustrated in Fig. 2, but arrangedto produce a spray which may be either iiner or coarser than that whichthe assembly shown in Fig. 2 is capable ci delivering. inasmuch as thepassageway for the material through the nozzle oi the assemblyillustrated in Fig. 3 will probably be of different dimensions, a valve3d oi proper size and its integrally formed valve 2l is supplied as apart of the assembly. Packing material 2t for the valve stem 37 islikewise provided.

The device may be readily converted by .means of these differentassemblies in the following manner. The head I8 is rst unscrewed fromthe restricted portion II oi the barrel, the end cap 38 is removed fromthe barrel, and the valve stem 21 withdrawn through the open end oi thebarrel. A head I3 having a desired type of nozzle thereon, and the newpacking material therein, is then screwed onto the barrel. Thesupplanting valve stem is assembled with the piston and the partsinserted in the barrel. The valves 2G and 53 are properly adjusted, theend cap 38 replaced on the barrel. and the -device is ready foroperation.

The assembly shown in Fig. 4 is adapted to produce a very heavy orcoarse spray and embodies a nozzle suitable for this prpose. In thisassembly, it may be desirable to provide a complete bearingmemberassembly 3l as well as a different piston assembly. This is in orderthat a proper cooperation between these parts and the supplanting valvestem 21 may be obtained. Otherwise, the manner of assembling the partswith the barrel is the same as has been described.

In Fig. 5 -means is shown for increasing the distance between the barreland the nozzle. 'I'his means comprises a tubular extension 1I having agland 'I2 at one end arranged to engage the screw threads formed on theforward end of the head I3. yThe other end of the extension is screwthreaded to receive a suitable nozzle assembly 13. The extensionlsadvantageous since the device, when used in connection with a paintapplying machine, is ordinarily mounted on a stationary part and itsadjustment relative thereto Is limited. Consequently, where it isdesirable to deliver the spray at some point which is beyond theordinary `limit oi.' adjustment, the extension 1I is employed.Obviously, thisp extension may be curved if desired while needles 21 ofcorat the end of y the extension.

It will beapparent from the foregoing that a novel device has beenprovided which is very simple in construction. The device is elcient inoperation, and is readily adapted for multiple use in batteries whichmay be simultaneously operated. Furthermore, the device may be convertedby merely replacing certain partsV with corresponding parts so that thedevice may meet all operating conditions and requirements.

I claim as my invention:

1. In a spraying device, the combination of means for creating andejecting a spray of coating material therefrom by pressure iluid, meansfor controlling the flow of coating -nutterial` thereto, -means forcontrolling the flow of pressure iuidl through said device, an operatormovable in response vto the force of said pressure iiuid, meansvconnecting said operator with said.

pressure fluid control means, a lost motion connection between saidoperator and said coating material control means whereby actuation ofthe responding length are used to shut oi! material operator eiectssuccessive movements of said control sure il d control means and saidcoating material control means acting separately to oppose movementthereof out of a normally closed position'.

2. A spraying device comprisingAn lcombination, a barrel having anemissionnozzle thereon and including an axially disposed materialpassageway and an air passageway located eccentrically of the axis, anaxial needle valve controlling the material passageway at the nozzle, anair valve concentric with said needle valve and controlling a ilow ofair to the air passageway, an

air operated piston in `said barrel rigid with said air valve andmovable when subjected to air pressure to open said air valve, saidneedle valve including a shank adapted to pass axially through and sliderelative to said piston, a head on said shank engageable by said pistonto open the needle valve after the air valve has been opened, springsengaging said piston and said shank to separately hold the valves.associated therewith normally closed, andan air inlet to said barrel inoperating communication with said piston.

3. A'spraying device comprising, in combination, a barrel having anemission nozzle thereon andincluding an axially disposed materialpassageway and an air passageway located eccentrically of the axis, aneedle valve controlling the material passageway at the nozzle, an airvalve controlling a iiow of air to the air passageway, an air operatedpiston in said barrel rigid with said air valve and movable whensubjected to air pressure to open said air valve, said needle valveincluding a shank adapted to pass through and slide relative to saidpiston, a head on said shank.

engageable by said piston to open the needle valve after the air valvehas been opened, and an air inlet tov said barrel in operatingcommunication with said piston.

4. A spraying device comprising, in combination, a barrel having anemission nozzle, an air operated piston therein spaced from said nozzle,an axial material passagewayy communicating with said nozzle, a needlevalve in Lsaid nozzle controlling the emission of material therefrom,said nozzle having a shank bearing in said piston and slidable relativethereto, a lost motion connection between said shank and said piston foractuating said needle valve, a passageway for airto said nozzle, an airvalve in said passageway connected with said piston for movementtherewith, and a passageway for delivering air under pressure to saidpiston and air passageway.

5. A spraying device comprising, in combination, a barrel formed oftransversely divided front and rear sections, said front section havinga nozzle thereon and a material passageway there-- in communicatingwith-said nozzle, a piston in said rear' section, communicating airpassageways in said front and rear sections, a needle valve forcontrolling a ilow of material through said nozzle and having a partextending into said rear section and operatively connected with saidpiston, an air valve actuated by said piston, and a. removable packinggland about said needle valve part including means adapted to be clampedbetweenthe front and rear sections when the device is assembled.

H6. A spraying device comprising, in combination, a barrel having anozzle thereon, means for supplying air under pressure and material tobe sprayed to said barrel, a valve controlling cans, and resilient meansfor said presthe ilow o1' material through said nozzle, a valve forcontrolling the flow oi air pressure to said nozzle, an` operator forthe valve controlling the flow of material to the nozzle including astem, actuating means mounted for slidable movement relative to saidstem under the 4influence of the pressure of incoming air and having anoperating connection with said air controlling valve, means on said stemdisposed for abutment by said actuating means in the relative slidingmovement thereof, and resilient means bearing individually on saidactuating means and on said stem for returning each separately to theidl positions thereof.

'1. In a spraying device, the combination o! means for creating andejecting a spray of coating material therefrom by uid pressure, meansfor controllingthe iiow of coating material thereto, means forcontrolling the flow of pressure uid through the spray means, anoperator movable in response to the force of said pressure fluid, arigid connection between said operator and said pressure fluid controlmeans, a lost motion connection between said operator and said coatingmaterial controlling means, whereby actuation of the operator effectssuccessive movements of said control means, and resilient means for saidpressure uid control means and said coating material control meansacting separately to oppose movement thereof out of a normally closedposition.

8. A spray gun comprising a body with a material passageway therethroughterminating at its front end in a discharge nozzle, a cylinder separatefrom said passageway, a piston in said cylinder, a needle extendingthrough said piston with its front end in cooperative relation to saidnozzle, means to admit iluid pressure to the front end of the cylinderto move said piston rearwardly, a spring in said cylinder opposing therearward movement of the piston, a head on the needle. valve engageableby said piston in its rearward movement to open said needle valve, and asecond spring acting on` the needle valve independently of the piston tooppose the opening of said needle valve.

9. A spraying device comprising, in combination, a barrel having anozzle thereon, controllable'means for supplying air under pressure andmaterial to be sprayed to said barrel, a valve controlling the ow ofmaterial through said nozzle and a valve operator for said valveincluding a stem, actuating means mounted for slidable movement relativeto said stem under the iniiuence of the pressure of incoming air, meanson said stem disposed for abutment by said actuating means in therelative sliding movement thereof to move said stem longitudinally foropening said valve, and resilient means bearing individually on saidactuating means and on said stem for returning each separately to theoriginal or closed position thereof.v

10. A spray gun comprising a body with a material discharge passagewaytherethrough, a needle valve cooperating with the discharge end of saidmaterial discharge passageway,` a spring tending to hold said valveclosed, a cylinder separate from said passageway, a reciprocable piston,a second spring acting on the piston to move it in one direction, saidpiston being movable by compressed air admitted to the cylinder inopposition to the spring, said piston having a motivating engagementwith the needle valve when moving in one direction and being movableinmunicating with said nozzle, a valve having pressure fluid responsiveactuating means for controlling the delivery of material to said nozzle,a conduit for delivering pressure fluid to said actu'ating means, a ductleading from a point adjacent tousaid actuating means for conveyingpressure iiuid to said nozzle to effect a spray of material therefrom,and a valve in said duct manually adjustable from a location exteriorlyof the device to control the iow of. pressure `fluid to the nozzle.

JENS A. PAASCHE.

